Apparatus for mixing finely-divided material and air.



A. G. KINYON L A. lfmcos. APPARATUS FOR MIXING FINELY DIVIDED MATERIALAND AIR.

APPLICATION FILED JUNE 2h |917.

Patented Mal'. 12, 1918.

Tomah I ressentie.,

ALONZO G. KON AND ARTHUR I. JACOBS, 0F CHICAGO, ILLINOIS, ASSIGNORS T0ECWDERED COAL ENGINEERING & EQUIPMENT COMPANY, 0F CHICAGO, ILLINOS. .ACORPORATION 01E DELAWE.

APPTUS FOR. MIXING FINELY-DIVIDED MATERIAL AND AIR.

To all whom it may concern.'

Be it known that we, ALoNzo- Gr. KINYON and ARTHUR I. JACOBS, bothcitizens of the United States, residing in Chicago, county of Cook, andState of Illinois, have invented new and useful Improvements inApparatus for Mixing Finely-Divided Material and Air, of which thefollowing is a specification. j

Our invention relates more particularly to means for mixing powderedfuel with air, though it will be obvious from the following descriptionthat it is clearly applicable for mixing other finely divided materialwith air where the conditions are substantially the same. Powdered fuelhas heretofore been employed in furnaces, kilns and the like by feedingit into a jet of air and thereby projecting it into the furnace whereadditional air is supplied to the fuel sufficient -to supportcombustion.A The mixture of the fuel with the air, however, especiallywith the additional air referred to above, commonly takes place quiteslowly and as the fuel is carried rapidly forward by the jet of airprovided for the purpose, there is but little combustion until the fuelhas been carried some distance from the burner and complete combustionis only effected after a considerable distance has been traversed by thefuel. The result of `this is that the dame is a long and slender onecomposed of rapidly moving air and fuel, the combustion of which beginsa considerable distance from the burner and it is impossible to developthe high degree of heat desirable in furnace work adjacent the burner.Such means for burning powdered fuel, is only available where thecombustion chamber is of sucient length to permit the gas and fuel underthe conditions mentioned to be completely mixed and burned. Even in suchconstructions there is but little heat developed adjacent the burner andthis part of the heating chamber is therefore for most purposessubstantially wasted. On the other hand, if the mixture of fuel and airmust follow a tortuous path because of bridge or cross walls or thelike, the latter are quickly destroyed by the impingement of the mixturethereon. lt is the object of this invention to so lthoroughly mix thefuel with the air for supporting combustion thereof prior to feeding thesame to the Specication of Letters Patent.

Patented Mar. i12, i948.

Application filed J une 21, 1917. Serial No. 175,987.

burner, that each particle of fuel is surrounded by an envelop of airsuiicient for the combustion thereof yand the air is as it.

were carbureted by the fuel` so completely that when itjemerges from theburner into the high temperature of the furnace, practically completecombustion takes place close to the burner, the mixture being fed slowlyforward and forming what is known yas a slow or lazy flame of greatvolume and little speed within the furnace.

ln the accompanying drawings we have shown and in the followingspecification described in detail the preferred form of our invention.`It is to be understood, however, that the specific disclosure is for thepurpose of exemplification only, the scope of the invention beingdefined in the followingvclaims, in which we have endeav- "ored todistinguish it from the prior art so far as known to us without,however, relinquishing or abandoning any portion or feature thereof. Inthe drawings Figure 1, is a vertical, longitudinal section of ourimproved apparatus for mixing powdered fuel and air, the parts beingshown in elevation, and Fig. 2 is a transverse vertical section thereofon the plane 2 2 of Fig. 1.

The improved apparatus comprises a cylindrical casing 3, inclosing amixing chamber, which is closed at its respective ends by end plates 4,5, and provided with an air inlet opening 6 and an outlet opening 7 forthe mixture of powdered fuel and air. rllhe mixing chamber properconsists of a perforated cylindrical screen 8 co-axial with the casing3, secured at one end 9 to an annular flange projecting inwardly fromthe head 5, and connected to an outlet 7 by a lateral branch or elbow11. The powdered fuel is fed to the mixing chamber from a hopper 12through a neck 13 formed integral and co-axial with the head 5 by ascrew 14 of small diameter carried by a shaft 15 extending through saidneck and beneath the hopper. rlhe shaft 15 extends completely throughthe neck and the casing, being journaled at one end in a bearing 16formed on a head 17 connected to said neck and at the other end in asimilar bearing 18 formed integral with a head 4. The bearings are shownprovided with suitable bushings 19, 20. The shaft 15 is illustrated as atube, though for the purose of this invention it need be 'such only fora short portion thereof between the end 22 of the mixing chamber and end2lof said shaft. Within the casing and extending substantially thelength of the mixing chamber and terminating at the inner wall of thehead 4 is an enlarged -perforated tube 23 which Iis concentric with andcarried by said shaft 15. Within the mixing chamber the tube 23 isprovided with successive annular series of perforations 24.substantially throughout its length and outside the mixing chamber butwithin the casing said tube is provided with annuli of largerperforations 25 which are in communication with the air space 26 of saidcasing. The tube 23 is plugged or closed at the end toward the hopper asat 27.

lt will be obvious from the construction as thus far described that theair entering at 6 under pressure flows in through the perforations inthe mixing chamber 8 into the interior thereof and also reaches theinterior of the mixing chamber through the inner. perforated cylinder orpipe23 which it enters by the openings 25 therein and escapes throughthe openings; 24. 'llhe amount of air entering the-mixing chamberthrough lto the sleeve 23 can be regulated by meansrof an internalsleeve valve 28 having ports 29 which may be brought more or less into'registry with uThe openings 25 by sliding the sleeve longit dinally.For this purpose a' rod 30 extends through the hollow shaft l5,

being provided at its inner end 31 with a cross piece 32 extendingthrough slots 33 in the vhollow shaft 15, said slots being ofv a lengthsucient to` permit the necessary.

movement of the sleeve 28 .to completely open. and close theholes 25.rlihe rod '30.. `may, if desired, be formed at its other end with ahandle, and a set screw 34 extends through the hollow shaft 15 and bearsupon said rod to secure it in adjusted position. Within the mixingchamber a erforated tube 23 is provided with a spira blade orribbon 35,which is mounted uponl but spaced from said'tube by the posts orsupports 36.

The operation of our improved air and fuel mixing device will beapparent from the above description thereof. Means are provided, suchfor example as the pulley 3'? for continuouslyrotating the shaft 15 andfor` forcing the required amountgof air under pressure through theopening d.A The openmg 7 is connected to a combustion chamber. for thefuel which may be a furnace, internal'combustion engine or other meansfor utilizinga mixture of' fuel vand air. 'llhe fuel is continuously fedinto the 'miming chamber by the revolution of the screw la and isimmediately taken .up b the manifold jets of air issuing into t echamber' through-the cpeningslboth inthe walls 8 and y22 ofv saidchamber and inl the tube 23.

Imeans for feeding powdered Landais lit is to be noted that the annularseries` of openings in the tube 23 are arranged intermediate oralternated with the series of openings in the wall of the chamber 8 sothat the jets are not directly opposed, but the jets from the tube 23are projected intermediate the jets from the openings in the wallSproducing a great number of small eddy currents, this ,edect' beingintensified by the 'support the combustion thereof. rlhe quantity orflow of air through the apertures in the tube 23 may be properlyproportioned with reference to the Vair entering through the aperturesin the mixing chamber wall by suitably adjusting the sleeve 28, asheretofore described. From the described apparatus the mixture of airand fuel is fed directly .to the burner, preferably without theVadmixture of other quantities of air. vlit venters the combustionchamber aty a relatively low rate of speed, because of the intimatecontact of the fuel with the air for supi porting combustion, and atonce bursts'into a Haine of high temperature, great volume and slowmovement, a so-called lazy dame, which evenly heats the furnace or othercombustion chamber throughout.

l. AA. mixing device for commingling air and inely divided mattercomprising a mixingl chamber, having a erforated wall, a casingsurrounding said c amber, means for supplying said casing with air underpressure-a rotary perforated tube within the ioo l casing, means forsupplyipgsaid tube'with air and f an outlet in the mixing chamber forthe mixture of fuel Aand air.,

lin a device ofthe class described, a mixing chamber having perforatedwalls, a casing. surround-ing the mixin chamber, o uel to the mixinchamber, an air inlet to said casing, an out et from said mixingchamber, a perforated tube within the mixing chamber communicatingwiththe casing outside said mixing chamber whereby the mixing chamber issupplied with air through the walls and through said tube.

3. lin a' device of the class described, a casing havin an air inlet andan outlet, a

mixing cham er within the Acasin means for supplyin the mixing cham erwith powdered fue a revoluble tube lwithin the casing and extending fora "portion of its length within the mixing chamber, perforations in saidtube within the mixing chamber and other perforations in said tubeoutside said mixing chamber but opening into l the casing.

4. In a device of the class described, a casing, a mixing chambertherein having perforated walls,means for feeding powdered material intosaid mixing chamber, a perforated revoluble tube within the casingextending partially within the mixing chamber, some of the perforationsof said tube communicating with the mixing chamber and other of saiderforations communicatwith the interlor of the casing outside saidmixing chamber and air inlet to said casin and the outlet from saidmixing cham er. p

45. In a device of the class described, a casing having an air mixingchambery within the casing having perforated' walls spaced from thewalls of l said casing, an

said casing, eating with the outlet of the casing, a revolubleAperforated tube extending partially within the mixing chamber andconnecting" with the air space 1n the casing; means for revolving saidtube comprising a shaft extending through one end of said casing, achamber surrounding said shaft and a hopper for feeding powderedmaterial to said chamber.

6. In a device of the class described, a

- casing, a mixing chamber within the casing and having erforated wallsspaced apart from the wal s of the casing, an air-inlet m outlettherefrom, means for feeding powdered fuel to the mixing chaminlet andanroutlet, a.

said mixing chamber commun1 ber and having perforations communicatingtherewith and partially extending without the mixing chamber and havingperforations communicating with the air space of the casing, a valve forcontrolling the last said perforations and means for adjusting thevalve'.

7. In a device f the class described, a casing, a mixing chamber withinthe casmg and having from the walls of the casing, an air inlet 1n saidcasing, an outlet therefrom, means for feeding powdered fuel to themixing chamber, a perforated tube in the casing extending partiallywithin the mixing chamber and having perforations communicatingtherewith and partially extending without the mixing chamber and havingperforations communicating with the air space of the casing, a lvalvemovable longitudinally of the tube for controlling thelast saidperforations, and means for adjusting the valve longitudinally of saidtube.

8. In a device of the class described, a casing, a perforated mixingchamber in the casing, means for feeding powdered mateperforated wallsspaced apart` rial to the mixing chamber, an outlet from the mixingchamber, a perforated tube communicating with the interior of the casmgoutside of and means for revolving said tube, a spiral ribbon mountedupon the tube within the charnwithin the mixing chambery

